Since the term “spintronics” was conceived in 1996, there have been several directions taken to develop new semiconductor-based magnetic materials for device applications using spin, or spin and charge, as the operational paradigm. Anticipating their integration into mature semiconductor technologies, one direction is to make use of materials involving Si. In this review, we focus on the progress made, since 2005, in Si-based half metallic spintronic materials. In addition to commenting on the experimental growth techniques, we review the computational models and the theory behind the non-spin-polarized and spin-polarized forms of density functional theory and the Kohn-Sham equations. Two software packages, associated with the computational methods, are also discussed. Both experimental and theoretical aspects, leading to recent design of half metallic quantum structures, will be reviewed.